1. Field of the Invention
The invention relates to a processor system, comprising a plurality of data processors, a communication network interconnecting said data processors so that said data processors can exchange information, a system memory, and a connection to the outer world, said system being such that various processes can be executed in the various processors while implementing a communication mechanism between different processes.
2. Description of the Prior Art
A multiprocessor system of this kind is known from U.S. Pat. No. 4,387,427 in the name of G. W. Cox et al, assigned to INTEL CORPORATION. This system is a rigidly coupled system which comprises a common memory which is shared by all processors and which is designed so that the impression of only a single processor is given to the outer world (be it a processor having a very high processing speed).
In such a set-up, however, the overall size of the system is inherently subject to a very severe upper limit, notably because the maximum number of processors is always limited, for example to less than ten.
The present invention aims to achieve a higher flexibility with several stations which appear to be separate vis-a-vis the environment so that the advantages of less rigidly coupled stations also become apparent. A station is a so-called hardware machine (HAMA), i.e. a locally present collection of parts intended for data processing, including the so-called system software which is intended for the control of these parts and which is an absolute requirement for any data processing operation. Each station comprises at least one processor which belongs to said parts and which serves to execute the various processes. These processors notably relate to the data processing operations which are controlled by "application software" in order to execute the information treatment intended by the user of the processor system. Therefore, it is an object of the invention to provide a processor system in which these application programs can be loaded without it being necessary for the user of the system to take account of the architecture of the stations; this is feasible in that, both with respect to one another and with respect to the environment, the stations can "hide" themselves as it were behind "mail box" spaces, each of which is exclusively associated with one super-process, so that the superprocesses also hide themselves as it were from one another and from the environment, behind these mail-box spaces; within one superprocess one or more processes can then be executed which can communicate and cooperate, for example wordwise, without reference to the mail-box mechanism so that user programs can be performed in a uniprocessor system as well as in a multiprocessor system and a system can remain operational in the case of failure of one or more stations, at least in as far as the elements required for an application remain operational in a sufficient amount for the remaining station (stations) or the relevant portion of the processing system to process the application. Elements are to be understood to mean herein apparatuses (for example, peripheral apparatuses) as well as program aids (for example, a conversion program between two data structures). A portion of the system is formed by one station or by a number of stations, provided that this number of stations can communicate among each other.